1. Technical Field
The present application relates to a drilling tool, especially for metallic materials, with generally at least two cutting edges and each with an at least partially spiraled flute extending from the cutting edges toward the tool shaft. This type of a drill bit is known from EP 0 750 960 B1, for example.
2. Background Information
Machining tools, especially drill bits, are often operated using cooling lubricants that are supplied to the tool's cutting edge or edges through coolant channels inside the tool. In the tool described in EP 0 750 960 B1, the central channel extending from the shaft-end splits into multiple sub-channels to which flute-shaped cross-channels break off at right angles at the cutting side end of the drill bit. The coolant supply is thus designed in a very complex manner.
U.S. Pat. No. 3,436,990 describes a drill with a central cooling channel which toward the forward drill tip divides into subchannels which are oriented diagonally outward with respect to the longitudinal axis of the drill. DE 101 57 450 A1 is concerned with the problem of feeding the coolant into the rear-side end of the drill shank and provides an insert via which the coolant is fed into the drill shank without large-angle deflections.